Influence of grassland and feeding management on technical and economic results of dairy farms

A field study of 38 dairy farms was set up to determine the relationships b etween feeding management, grassland management and feed costs per 100 kg o f milk, 305-day milk production, and nitrogen surplus per ha. Data of the f arms were (among other things) on management (based on questionnaires), gra ssland calendar, milk production and economic data for the period of May 19 96 to May 1997. Partial Least Squares (PLS) was used to analyze the data, b ecause of the large number of variables relative to the number of farms. Th e R-2 Of the models ranged between 0.32 (nitrogen surplus model) and 0.60 ( feed costs model). The nitrogen surplus model did not have predictive relev ance. The PLS-model for feed costs resulted in the hypotheses that (1) a hi gh percentage of pasture that cannot be grazed by the cows results in an in crease in feed costs, (2) a high percentage of grazings lasting longer than 4 days increases feed costs, (3) mistakes in set-up of the paddocks cannot be compensated for by exact planning, and (4) farmers who have not organiz ed their grazing;management well, also tend to have worse results as to the ir silage management. The milk production model showed that a high milk pro duction per cow is realized on farms with too low a number of growing days for cutting.